Updated at: 15-06-2022 - By: Sienna Lewis

Three methods exist for growing asters if you’d like to do so. Asters, unlike many other plants, can be grown from seed, cuttings, or divisions. This gives you an advantage because you may choose the method that works best for you.

Even though asters can withstand harsh weather, growing them in a greenhouse may be your best option. Gardeners can rest easy knowing that their young, delicate plants are sheltered from the effects of a changing climate when they begin their seedlings in a greenhouse. As a result, no matter what method you use to root asters, you should think about doing so in a greenhouse to avoid any complications later on.

Benefits of Division

Even while asters gladly self-proliferate, they are healthier, prettier and better-behaved if they are divided every few years to keep them in check.

Aster × frikartii 'Mönch' - Michaelmas Daisy - Garden Plants

It also makes it easy to propagate your own plants and increase the number of plants in your yard, or to share them with your friends.

Seeds of native species can be saved, but those of cultivated species cannot.

In order to get the most out of your asters, divide them every few years. Powdery mildew can be inhibited by increasing airflow by reducing clump density.

How to Divide Perennial Asters

The Asteraceae family includes asters, which grow in clumps.

In either case, the revitalizing effects of periodic division will benefit all of your plants, no matter how large or small they are.

Dividing them when the new branches are starting to grow in early spring is the optimal time to do it. Over the summer, the new divisions will have time to establish themselves.

If you wait until the buds appear, you’ll have to wait until the next year.

The growth of a clump is homogeneous across a healthy one. Patchy growth and perhaps even a center of bare dirt are signs that the plant needs to be divided.

As a plant ages, the heart of the clump dies, and new growth springs out around the outside of the plant.

You have two options for dividing your plant: either cut the roots in situ and only dig up a part, or dig up the entire plant and separate it. Both methods work.

Afterwards, you’ll be able to plant the fresh divisions either in pots or in the garden.

To see how they differ, let’s compare and contrast.

Cut and Separate

First, cut through the clump’s roots one or more times to separate it.

In this manner:

Make an incision with a spade into the center of the plant, cutting it into two pieces.

After cutting the cluster in half, the next step is to dig a trench around it, a few inches in from the edge. A shovel can be used to loosen and remove the chopped piece from the ground.

Using your hands, gently remove any loose soil from the roots and return it to the hole. As needed, add more soil to the hole.

Use a pair of sharp pruners to remove any dead plant material from the clump you’ve just removed. One or more new branches with roots and dirt attached should result from this procedure.

Young plants are the ideal candidates for this technique. Older trees may have bare spots in the ground, giving in a lanky, patchy appearance in the fall.

Dig Up and Separate

In the second approach, the entire clump is dug out, and each portion is replanted.

Plants can be unearthed by applying foot pressure to dig a trench a few inches outside the perimeter of new shoots. Each time you dig, gently push the shovel forward to dislodge the roots. You should be able to loosen the entire cluster with your final dig.

Remove loose soil from the roots by placing the plant over the hole and removing it with your hands.

Tease apart the roots to release the peripheral shoots from the clump. You might have a single one or numerous clusters. Sharp pruners can be used if necessary to remove the shoots from the plant.

As you go around the perimeter, cut away the outermost shoots and roots in portions. If the plant doesn’t have any new shoots, toss the center and any dead leaves into your compost pile.

For a more consistent, compact look at bloom time, this procedure allows you to eliminate all dead material.

Slideshow 1903-06: Blue flowers of Michaelmas daisy (Aster amellus...Institute. St.Petersburg, Russia

After you split a plant by one of the two techniques described, you can either pot up or transplant your clusters of tender shoots.

Pot Up or Transplant

Depending on how you split the plant, you can either pot the vulnerable shoots or transplant them.

To reassemble the freshly split portions, follow these directions:

In a well-draining compost or potting media, pot up each new plant.

Pots should be placed in a bright yet shady spot, with regular misting to keep soil evenly moist.

When the risk of frost has gone, follow the procedures below to transplant outdoors.

To grow in the garden, use the following instructions:

New divisions should be spaced at least 18 inches apart and on well-draining soil, in full sun to light shade

Fill in the previous hole with soil or compost if you’re replanting in the same spot, as the new division will be too deep. Alternatively, create a hole that is somewhat larger than the root you intend to plant.

To avoid burying any of the sprouts, carefully place your division in the hole and cover with soil. Tilt the soil and thoroughly wet the seeds. While the plants are getting established, make sure to keep the soil evenly moist. Mulch surrounding each new clump helps maintain moisture and discourages the growth of weeds.

A slow-release fertilizer like 10-10-10 (NPK) can be used later in the spring to foster strong development.

Time for the Task

It’s better to divide existing plants in the spring so that young ones have time to adapt before the summer heat kicks in. It also provides them enough time to start setting buds in preparation for a fall bloom.

We wouldn’t have blossoms till the following year if we split clusters in the summer. It’s conceivable that they’d be killed by frost if we planted them in the fall.

Divide and Conquer

When it comes to perennial asters, you don’t have to worry about them being difficult to maintain.

The more control you have over your flowers, the more appeal they’ll provide to your outside space, especially if you keep them compact and rich rather than sprawling and scraggly.

While some of your asters may need to be divided every two or three years, others may be able to go for three or more years without exhibiting signs of overcrowding or dying.

For even more height and stability, cut the top third of the leaf off by Flag Day in June to stimulate lateral branching and more stability.

Do you have any questions or concerns about dividing perennials? Please share your thoughts in the space provided.

You’ll need the following guides to learn more about aster gardening:

How To Propagate Asters Successfully

Option #1. Seeds

Asters may be grown from seed, unlike most perennials. Let your aster plants self-seed, or gather them from existing plants. Seeds that look like dandelion seedheads can aid in the success of reproduction in the garden.

Aster seeds germinate in 20 to 30 days, according to researchers at the University of Florida. But if you start them indoors, such in a greenhouse, you may reduce this time to just 15 days. You must emphasize that these periods can only be achieved if the aster seeds are properly sown.

You should sow two seeds at 18 inches deep in seedling pots, using a sterile and wet potting mix. After planting, spritz the pot and cover it with a plastic bag to avoid having to water the pots on a regular basis. The medium should still be checked for moisture and mist if necessary, so be aware of this.

Once the seeds have sprouted, you can remove the plastic cover and move the pots to a location that receives all-day sun. As the asters mature, use scissors to remove the weaker ones and transplant the strongest ones after the first frost. However, if the outdoor conditions are too difficult, you can continue to grow the asters indoors.

How To Grow Asters (Aster Flower) - BBC Gardeners World Magazine

Option #2. Cuttings

Asters can be propagated from seeds, although cuttings or divisions offer a number of advantages over this method. These two approaches are the only ones that will allow you to make an exact clone of a species. Due to cross-pollination or hybridization, it is not certain that a seed-grown plant will appear exactly like the parent plant.

On the other hand, using cuttings or division is a reliable way to create clones of a parent plant that you like. So how does one propagate asters from cuttings? Depending on the variety, you can root them from softwood cuttings.

Most gardeners use sand or perlite as a medium and cover the pot with a clear plastic bag to encourage root growth. The only maintenance methods that remain are keeping the soil moist, providing light, and clipping the cuttings as they begin to root.

Option #3. Division

Asters can also be multiplied through division, which is another method of cloning them. If you have a lot of mature asters that you can divide every three years as they get big enough, this is a great option for you. Do asters need to be divided at a specific time of year?

When the flowers begin to fade in the spring, it is typical to divide asters. It is the quickest and easiest method to divide a plant into two equal parts. Using a shovel, carefully lift each piece and remove all of the loose soil from the roots.

You should remove all the dead plant material before planting so that you are left with young branches and roots with some soil. If you want, you can remove the entire plant and divide asters this way. Now, how do you divide an aster?

It’s best to grow plants indoors in a wet potting media that stays that way. You should wait until the threat of frost has gone if you intend to transplant directly into the garden, however. 18 inches between each division in the garden can be accommodated in holes slightly larger than the root diameter.


Do you want asters in your garden, or would you like to see more of them? Asters can be grown from seeds, cuttings, or divisions, and each method has its advantages and disadvantages. With seeds, the asters will not resemble their parent plants in any way, shape, or form when they are grown.

Using cuttings and divisions, on the other hand, ensures that you get multiples of your preferred asters. Propagating aster is best done in spring, and the plants can also self-seed. It’s also possible to divide a plant into two root parts for the other methods, such as 5-inch cuttings.

There may be a trend toward keeping the medium moist and even covering the young plants with plastic, regardless of whatever approach you choose Starting asters in a greenhouse and moving them outside once the threat of frost has gone is an option.